Oil well mud pump valve



y 1956 R. K. SHELLMAN 2,745,631

. OIL WELL MUD PUMP VALVE Filed Oct. 23, 1952 ATTORNEY- United States Patent 2,745,631 OIL W'ELL MUD PUMP VALVE Roy K. Shellman, Compton, Califi, :assignor to Mac- Clatchie Manufacturing Co., Compton, Cali, 2 corporation of California Application October 23, 1952,'Serial'No. 316,347 1 Claim. (Cl. 251-175) This invention relates to improved valve structures particularly adapted" certain respects for use as fluid inlet and outlet check valves in high pressure pumps, as for instance in oil well mud pumps.

The operating pressures of an oil well mud pump are usually extremely high, with the result that the inlet and outlet valves of the pump are opened and closed rapidly and with very great force. Consequently, unless the valves are of a special wear resistant construction, their repeated closures tend to quickly damage the engaging surfaces of the valve and its seat, andsoon render the valve ineffective to close off 'fluid'flow. For this reason, it has heretofore been proposed to provide the movable valve element and its seat with interengageable stop shoulders (in addition to the main valve surfaces), which act to limit closure of the valve element and thus prevent damage to the sealing surfaces. These stop shoulders have heretofore been formed at an inner side of the valve element inwardly beyond the seat surface in the direction of valve closing movement. In order that the valve seat may be of a construction to prevent a stop shoulder at that location, the seat has generally been formed as a forging, usually having a valve guide portion as well as the stop shoulder at the inner side of the valve structure.

The general object of the present invention is to provide an improved valve of the above discussed type which is so constructed as to overcome certain disadvantages or limitations of prior such valves. For one thing, the present valves are so designed that their stop shoulders may have a considerably greater striking area than has been possible in prior devices, so that the shoulders may resist damage for an increased period of use. Further, the valve shoulders are so positioned relative to the valve seat surface as to permit formation of the main seat structure from ordinary tubular stock, instead of requiring its special construction as a forging.

The present valve units preferably differ from prior similar valves in that the closure limiting stop shoulders are positioned at the outer rather than inner side of the valve, that is, they are offset in the direction of valve opening movement from the main valve seat surface. As will be appreciated, there is considerably more space at the outer side of the valve than at its inner side for accommodating stop shoulders of an increased striking area, and to do so without unduly obstructing the path of fluid flow through the device. Also, when the stop shoulders are positioned at the outer side of the valve, the shoulder on the seat structure may be formed as merely an end surface on a piece of tubular stock, without requiring that the seat be a forging to carry a stop shoulder inwardly beyond the main seat surface.

Preferably, the stop shoulder on the valve seat structure is located farther from the valve axis than is the valve seat surface. This feature, like the positioning of the stop shoulders at the outer side of the valve, considerably increases the possible striking area of the stop shoulder.

The above and other features and objects of the present position.

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2 invention will be better understood trom'the following detailed description of the typical embodiments illustrated in the accompanying drawing, inwhich: a

Fig. 1 is a perspective view of a "first 'form of oil well mud pump valve embodying the invention; i

Fig. 2 is an axial section through the Fig. '1 valve; and

Fig. 3 is an axial section through a variational form of the valve embodying the invention. i

The oil well mud pump .check valve "10 shown in Figs. 1 and 2 includes a seat section 11 and .a movable'valve unit 13. The seat section 11"i s annular and typically formed of a short length of metal tubing. At its inner side, seat 11 has an annular inclined upwardly facing seat surface 14 against whichan annular inclined downwardly facing surface 15 of deformable element 16 of the valve unit 13 seats in closed condition of the'valve. At its upper end, seat .11 has an annularsurface or'shoulder '17, which preferably extends directly transversely .of the valve axis, and is engageable'by transverse shou'lder'25 at the underside of flange "26 of valve unit '13'to liriiitLits downward or closing movement. The verticallymovable valve unit 13 includes a vertically extending stem 27, which carries the above mentioned transverse stopfflange 26. The upper end. of stem .27 may be guided -for the desired vertical'movement by reception within boref2 8yin a guide member '29, with the valve unit being yieldingly urged downwardly to closed condition by spring 30.

Beneath flange 26, valve stem 27 carries a resiliently deformable annular seat engaging element 16, which may include a main rubber portion 31 and fabric or plastic reinforcing 32. The inclined seat engaging surface 15 of deformable element 16 is preferably disposed at a slightly greater angle to the valve axis than is the seat surface 14, to assure the formation of a most effective fluid seal between the parts. Element 16 may be backed at its upper side against the central portion of flange 26, which is in turn backed against an integral flange 38 on stem 27. The outer portion of valve element 16 is axially spaced from flange 26 at 137, to provide an annular space into which fluid may flow through circularly spaced openings 35 in the flange to urge element 16 downwardly against its seat. As will be understood, the force of such fluid acts in the closed condition of the valve to urge the valve element tightly against its seat 14.

A rigid retaining member 34 is provided about stem 27 beneath valve element 16, with a bottom nut 40 being screwed onto the stem therebeneath, to tighten elements 34, 16 and 26 upwardly against the stem flange 38. Nut 40 preferably carries a number of circularly spaced outwardly projecting guide fins 140, slidably engaging bore 41 in seat section 11, to cooperate with upper guide member 29 in guiding the valve for its vertical opening and closing movement.

In use, the valve of Figs. 1 and 2 is normally urged by spring 30 to its closed position of Fig. 2, in which surfaces 14 and 15 form a tight fluid seal. The downward closing movement of movable unit 13 is limited in the Fig. 1 position by engagement of stop shoulders 24 and25 on seat section 11 and flange 26. When the fluid pressure beneath the movable valve unit 13 reaches a predetermined value, unit 13 moves upwardly, to pass fluid upwardly past seat surface 14 and flange 26. When the pressure at the underside of the valve subsequently decreases, spring 30 and the fluid pressure at the upper side of the valve return unit 13 downwardly to closed By virtue of the interengagement of stop 25, the closing movement of the valve is limited, regardless of how great the closing force may be, without damage to seat surface 14 or deformable element 16. It also will be seen that the inward axial spacing of the sealing surface 15 of the element 16 from the stop surface 25 on the flange 26 precludes any pinching off of the element 16 as the surface 25 slams against the stop surface 17. Furthermore, because of such spacing, the radially inwardly directed fan-shaped jet squeezed from between the surfaces 25 and 17 as the valve closes, does not detrimentally impinge on the sealing surface 15. In order that the limitation of valve movement may be as eifective as possible, and to assure a minimum wear on the parts, seat section 11 and flange 26 are preferably formed of a suitable very tough and hard steel or other metal.

The Fig. 3 valve is substantially identical with that of Figs. 1 and 2, except astto the manner in which the lower end of the movable valve unit is guided for vertical movement. Specifically, in Fig. 3, nut34a does not carry guide fins corresponding to those shown at 40 in Fig. 2, but

instead has a lower cylindrical guide portion 42, which is slidably received within and engages cylindrical bore 43 formed in a spider 44 carried by thelower portion of seat section 11a. As will be understood, spider 44 is formed integrally with seat section 1112, and includes at least one, and preferably several, circularly spaced radial webs 45, carrying an innervannular portion 46 within which guide bore 43 is formed;

I claim: v

A reciprocating valve'comprisin gz. a rigid valve seat having an annular concavo-conoidal sealing surface and an annular substantially fiat stop surface ofiset both radially and axially outwardly of said sealing surface; and a reciprocable valve unit seatable on said seat, said unit comprising a stem member, means defining a rigid circumferential flange fixed on said stemmember against outward movement relative thereto and having an annular stop surface opposed and complementary to said seat tion of the valve, and a yielding pressure-deformable sealing ring coaxially mounted on said stem member inwardly of said flange and having an inner peripheral portion fixed against axial movement relative'to said stem 10 member and an outer peripheral sealing surface opposed 20 valve.

References Cited in the file of this patent UNITED STATES PATENTS 25 758,012 Marsh Apr. 19, 1904 1,654,772 Akerson Ian. 3, 1928 2,255,404 White Sept. 9, 1941 2,402,713 Volpin June 25, 1946 2,495,880

Volpin Ian. 31, 1950 stop surface for abutment thereagainst in the closed posi- 

